LevelDBProto: Remove unnecessary reinterpret_cast

The expression already has the specified type.

Bug: None
Change-Id: I49ac50699182978380f964959957ea1001046b8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2435920
Commit-Queue: ssid <ssid@chromium.org>
Auto-Submit: Kevin McNee <mcnee@chromium.org>
Reviewed-by: ssid <ssid@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811392}

components/leveldb_proto/internal/unique_proto_database_unittest.cc

@@ -551,9 +551,7 @@ TEST_F(UniqueProtoDatabaseTest, TestDBRemoveKeys) {
         std::move(signal).Run();
       },
       run_update_entries.QuitClosure());
-  ProtoDatabaseImpl<TestProto>* wrapper =
-      reinterpret_cast<ProtoDatabaseImpl<TestProto>*>(db_.get());
-  wrapper->RemoveKeysForTesting(
+  db_->RemoveKeysForTesting(
       base::BindRepeating([](const std::string& str) { return true; }),
       kTestPrefix, std::move(expect_update_success));
   run_update_entries.Run();